Non-metallic strap jointing apparatus, especially for heat sealing straps

ABSTRACT

Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising means for drawing the end strap portion in a direction tending to tension the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, and locking means for locking said end strap portion near said region and before said region with respect to said direction.

United States Patent 1191 Roquier-Vicat Jan. 2, 1973 54 NON-METALLIC STRAP JOINTING 3,539,416 11/1970 Sanders et al. ..l56/583 x 3,442,735 5 1969 Stensaker APPARATUS ESPECIALLY FOR HEAT 3,494,280 2/1970 Kobiella ..l56/580 x SEALING STRAPS Inventor: Camille Roquier-Vicat, Paris, 14

Siene, France Assignee: Imhanda A/G Filed: March 17, 1970 Appl. No.: 29,372

Foreign Application Priority Data March 20, 1969 France "6908096 US. Cl ..l56/380, 156/580 Int. Cl ..B29c 19/02 Field of Search ..l56/380, 580, 583

References Cited Primary Examiner-Benjamin A. Borchelt Assistant Examiner-H. Tudor Attorney-Breitenfeld & Levine [5 7 ABSTRACT Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising means for drawing the end strap portion in a direction tending to tension the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, and locking means for locking said end strap portion near said region and before said region with respect to said direction.

7 Claims, 4 Drawing Figures PATENTEUJMI 2 I975 SHEET 2 [IF 3 IN VEN- TOR:

CHM/LLE Rood/em VIM-r Arrokuevs PATENTEDJAN 2 ms SHEEI 3 OF 3 g W7 u f i INVENTOR. Cam: Roqwm- VIcRT NON-METALLIC STRAP JOINTING APPARATUS, ESPECIALLY FOR HEAT SEALING STRAPS The invention relates improvements to non-metallic strap jointing apparatus, especially for heat seatable straps.

More precisely, the invention relates to apparatus which, to secure together by heat sealing the overlapping initial and end straps of a tensioned strap look, comprises tensioning means for the end strap and heat sealing means for the overlapping portions.

According to a first feature of the invention, the apparatus is provided with locking means for the end strap upstream of the sealing portion in the strap tensioning direction and adjacent to the said portion, said locking means being considered as essential, when the end strap is cut before heat sealing for, the strap tension around the article to be hooped not to be reduced by the self adjustment of the strap.

Moreover, the locking means allows use of the capstan type tensioning device which is the only one which provides the maximum tension for a looped strap According to another feature of the invention, the apparatus is provided with end strap cutting means which comprises a movable cutter which by its movement provides bringing together straps to be sealed and pressure necessary for sealing.

The invention also relates to a heat sealing apparatus particularly adapted for sealing non-metallic heat sealable straps.

Known strap sealing apparatus generally comprise a flattened head containing a heating resistor which is temporarily interposed between the heat sealable materials to soften them preparatory to sealing. The invention provides the use of an about 45 Watts releasing resistor and provides supplying the resistor a voltage source not more than about 24 volts.

This power is the best adapted for most heat sealable straps and low voltage reduces electrocution risks.

These features of the invention and some other features will appear in the description below referring to drawings illustrating an embodiment of a strap sealing apparatus comprising the invention improvements.

FIG. 1 ,is an elevation of the apparatus in a plane parallel to the plane of a strap sealing loop;

FIG. 2 is atop plan view of the apparatus illustrated in FIG. 1, I

FIG. 3 is a section of the apparatus along line AA of FIG. 1, and

. FIG. 4 is a section of the apparatus along line 8-3 of FIG. 1.

The illustrated apparatus comprises a base 1 to be shifted between strap and article to be strapped, as well known in the art. The base carries a lower stationary jaw 2 and a movable jaw 3 which can be forced towards jaw 2 and which is biased away from the stationary jaw by spring means. The two jaws are included in the initial strap locking means.

A strap is schematically illustrated in FIG. 1 by broken line 4 4a refers to the initial strap which is supposed to form a sealing loop around an article (not shown) under base 1. After surrounding the article, the strap presents an end strap 4b which can be tensioned by a capstan schematically shown at 5.

The apparatus comprises heat sealing means to heat seal together the initial and end straps. The heat sealing means are not described in detail because they are known means selected by one skilled in the art according to the kind of strap, the strap generally being a heat sealable plastics strap.

In the drawings heat sealing means are schematically represented by assembly 6 and 6. Such means is located between the initial strap locking means and the end strap tensioning capstan.

. Moreover, the apparatus comprises strap cutting means between the heat sealing zone and the capstan, said means being schematically represented by the cutters 16, 17. The cutting means will not be described in more detail, because they aremeans well known by one skilled in the art.

However, according to another feature of the invention, cutting means comprises a movable cutter l6 and a stationary cutter 17, the two cutters engaging to cut the strap after heating of straps to be heat sealed but before the effective heat sealing. So, end the strap imperceptibly moves backwards, sufficiently to apply completely the cut end on the initial strap without forming an unsealed projection.

According to a feature of the invention, the movable cutter by its vertical movement provides on the one hand bringing together the initial and end straps and on the other hand pressure necessary for sealing.

According to the invention, the apparatus comprises end strap locking means.

In the illustrated embodiment, said means comprises two jaws, the strap crossing between them, and a pressure member locked to one of the jaws which is movable by control means in a direction to bring together the jaws, said member'being movable in the opposite direction by return spring means to move aside the jaws.

According to the invention, itis advantageous to provide the jaws with a V-profile which contributes to tightly pressing the straps in the vice formed by the aws.

In the illustrated embodiment, one of the two jaws is constituted by the upper jaw 3 of initial strap locking means and the other jaw 8 is locked on a pressure member constituted by a pin 9, as best seen in FIG. 1. This pressure pin is biased by a spring 10 which pushes the pin upwardly to bring jaw 8 away from jaw 3. The downward slide of the pressure member 9 is controlled by means comprising, according to the invention, a cam 11 pivotably mounted and pivotable by a partly shown lever 12 (FIG. 1) and a tilting member 13 pivotably mounted about a pivot 14 parallel to the rotation axis 15 of the cam. Member 13 presents a contact surface 13a contacting the cam surface of cam 11 so that the cam, depending upon the surface portion contacting the tilting member, controls the tilting of this member in a direction such that pressure member 9 is pushed downwardly to bring together jaw 8 and jaw 3, or leaves it to tilt in the other direction by action of spring 10, after completion of heat sealing as lever 12 is brought again to its initial position.

In the illustrated example, the cam is particularly simple as its action surface comprises a flat surface lla between two cylindrical surface portions 11b and 11c.

In the illustrated position, wherein the tilting member is contacting the flat surface of the cam, jaws 8 and 3 are away from each other.

The lever 12, which controls end strap locking or unlocking, is also designed to control cutting of the end straps.

In a preferred embodiment, this lever is also used to control the operation of its sealing device.

It will be understood that the lever is only a particularly simple example of control means for general operation of the apparatus, but the invention does not exclude any other means and for instance control means with a push-button or knob, mechanical or electromechanical. The operation of an improved apparatus according to the invention is distinguished from the current practice by the fact that the end strap is cut after heating and before sealing with the initial strap.

Moreover, in a strapping process according to the invention, the operations successively effected are locking the initial strap, tensioning the end strap, locking the end strap, heating the straps, cutting the end strap and heat the sealing straps together.

The end strap locking means prevents a backward movement of the cut strap and strap cutting before heat sealing makes it possible to seal the entire cut strap initial strap.

What is claimed is:

1. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, said end strap portion locking means comprising a pressure member movable in a first direction for bringing said two jaws together, control means for moving said pressure member in said first direction, and spring means biasing said pressure member in a second direction opposite to said first direction.

2. Jointing apparatus according to claim 1 wherein saidjaws are V-shaped.

3. Jointing apparatus according to claim 1 wherein said control means comprises a cam pivoted bya lever and a tilting member controlled by said cam in such a manner that, depending upon the position of the cam with respect to the tilting member, said pressure member is pushed by said tilting member either in said first direction or in said second direction.

4. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, a single means being used for successively effecting the locking of said end strap portion, the heating of the said strap portions, the cutting of the said end strap portion, and the sealing of the said strap portions.

5. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tension-ing means including a capstan for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws.

6. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, and end strap portion cutting means, said cutting means comprising a cutter movable for bringing said strap portion together with sealing pressure.

7. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, said. three jaws being vertically aligned, and the middle one of said three jaws cooperating with the jaw above it to define said end strap portion locking means, and said middle jaw cooperating with the jaw below it to define said initial strap portion locking means. 

1. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, said end strap portion locking means comprising a pressure member movable in a first direction for bringing said two jaws together, control means for moving said pressure member in said first direction, and spring means biasing said pressure member in a second direction opposite to said first direction.
 2. Jointing apparatus according to claim 1 wherein said jaws are V-shaped.
 3. Jointing apparatus according to claim 1 wherein said control means comprises a cam pivoted by a lever and a tilting member controlled by said cam in such a manner that, depending upon the position of the cam with respect to the tilting member, said pressure member is pushed by said tilting member either in said first direction or in said second direction.
 4. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, a single means being used for successively effecting the locking of said end strap portion, the heating of the said strap portions, the cutting of the said end strap portion, and the sealing of the said strap portions.
 5. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tension-ing means including a capstan for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws.
 6. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said sTrap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction, further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, and end strap portion cutting means, said cutting means comprising a cutter movable for bringing said strap portion together with sealing pressure.
 7. Jointing apparatus for securing together by heat sealing an initial strap portion and an end strap portion of a tensioned strap forming a loop, said apparatus comprising tensioning means for drawing the end strap portion in a direction for tensioning the strap, heat sealing means for sealing together said strap portions in a region where they are in overlapping condition, locking means comprising two jaws for locking said end strap portion near said region and before said region with respect to said tensioning direction and further locking means for locking said initial strap portion, said initial strap portion locking means comprising a jaw located under said end strap portion locking jaws, said three jaws being vertically aligned, and the middle one of said three jaws cooperating with the jaw above it to define said end strap portion locking means, and said middle jaw cooperating with the jaw below it to define said initial strap portion locking means. 